Brake rigging



E. G. MUELLER BRAKE RIGGING May 2, i950 2 Sheets-Sheet l Filed April 10, 1946 May 2 1950 E. G. MUELLER 2,505,986-

BRAKE RIGGING Filed April 1o, 194e sheets-sheet 2 INVENToR. Emil 6. Medel? BY @im atented May 2,

BRAKE RIGGING Emil G. Mueller, Churchill Borough, Pa., assignor to The American Brake Company, Swissvale, Pa., a corporation of Missouri Application April 10, 1946, Serial No. 660,997

(Cl. 18S- 56) 22 Claims.

My invention relates to brake rigging for railway rolling stock, and particularly to brake rigging of the unit cylinder clasp type which is particularly suitable for, although in no way limited to, use on the trailer trucks of locomotives.

In a new design of steam turbine electric locomotive the space which in previous designs had been available for brake rigging between the wheels of the trailer truck is taken up by motors and gears which are associated with the axles, and the space which otherwise remains for the brake rigging is limited to such an extent by the frame and other parts of the locomotive that it is extremely difcult to provide the trailer truck With suitable clasp brakes.

One object of my present invention is to provide brake rigging of the unit cylinder clasp type which can be mounted in the limited space available on the trailer truck of a steam turbine electric locomotive of the type described.

Another object of my invention is to provide a clasp brake rigging having a positive release action and in which shoe dragging difficulties are eliminated.

A further object of my invention is to provide a clasp brake rigging of the type described incorporating an automatic slack adjuster.

According to my invention, each wheel of the truck has associated therewith a brake cylinder located above the wheel in the same vertical plane as the wheel as close as possible to the center of the truck. The piston rod of the brake cylinder is inclined upwardly at a slight angle, and is pivotally connected at its free end to the upper end of a floating brake cylinder lever which is pivotally supported intermediate its ends by a pair of laterally spaced transmitting hanger levers, and which brake cylinder lever carries at its lower end a brake head provided with a brake shoe for frictional engagement with the wheel. The transmitting hanger levers are pivotally attached at their upper ends to the truck frame and are operatively connected at their lower ends to a pair of straddle rods. The straddle rods are provided at each end with pin hole take ups, and are pivotally connected at the `ends opposite to the transmitting levers with the lower end of a slack adjuster live lever. The slack adjuster live lever, in turn, is pivotally attached to the lower ends of two laterally spaced hangers by means of a pivot pin which also serves to secure to the slack adjuster live lever a brake head carrying a brake shoe for frictional engagement with the adjacent wheel. The upper ends of the hangers, which support the slack adjuster live lever are pivotally attached to the truck frame. The slack adjuster live lever at its upper end is operatively connected by means of a transversely extending vertically olset adjusting lever to an automatic slack adjuster secured to the truck frame outboard of the wheels in a position where the slack adjuster is readily accessible for inspection, adjustment or repair. The brake rigging also includes means for eiecting a quick release of the fbrakes as well as means for preventing the brake shoes from dragging when the brakes are released.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of brake rigging embodying my invention, and shall then point out the novel `features thereof in claims.

In the accompanying drawings, Fig. l is a side elevational view showing brake rigging embodying my invention applied to a four-wheel trailer truck. Fig. 2 is a top plan View of the brake rigging shown in Fig. l with some of the parts omitted to simplify and clarify the drawing. Fig. 3 is a left-hand end View of the brake rigging shown in Fig. 1. Fig. 4 is a view of the portion of the brake rigging associated with the left-hand Wheel in Fig. l as viewed from the right in Fig. 1. Fig. 5 is an enlarged detail view of a portion of brake rigging illustrated in Fig. l.

Similar reference characters refer to similar parts in each of the several views.

Referring to the drawings, the brake rigging here shown is applied to a four-wheel trailer truck provided with a frame l supported at its forward end by a wheel and axle assembly comprising a pair of wheels 2 mounted on an axle 2a, and at its rear end by a wheel and axle assembly comprising a pair of wheels 4 mounted on an axle 4a. The means for supporting the truck frame l by the wheel and axle assemblies is not shown because these means are well known and form no part of my present invention.

The brake rigging comprises four separate sets of mechanisms one set of which is provided for each wheel. These mechanisms are similar and it is believed, therefore, that an understanding of the entire brake rigging will be had from a description of the mechanism which is associated with one only of the wheels.

Referring particularly to the mechanism associated with the one wheel 4, for example, this mechanism comprises a brake cylinder Ca, which for clearance reasons-is secured to the frame l in an inclined position directly above the wheel #i in the same vertical plane as the wheel as close as possible to the center of the truck. This brake cylinder is of the usual type, and includes the usual cylinder portion,"piston and return spring (not shown); and'push rod 5 operated by the piston.

The push rod E extends past the wheel and is pivotally connected at its free end to the upper end of a oating brake cylinder lever t. The iloating brake cylinder lever is pivotallymounted intermediate its ends on a pivot pin "l extending through two laterally spaced depending hanger levers intermediate their ends. r.Ihre hanger levers s are pivotally attached at their upper ends to the truck vframe by means of laterally spaced pivot pins S. (see Fig. 3) mounted in suitable supporting lugs le provided on the frame 1| .on opposite sides of the iloating cylinder lever 16, and are spaced from the floating cylinder lever by means of 'suitable spacing sleeves it provided .on the pivot 'pin l. The pivot pin 'E is threaded toirecei've nuts l2 which maintain the parts in piace.

l".'lhe lower end of the oating cylinder lever x6 carries a brake head I3 'provided with a brake shoe i4 for frictional engagement with the wheel 4 `at oneside of the wheel. The brake head is secured to the floating cylinder lever by means .of la pivotpin l5 which also serves to secure to the lever friction arms I6. These arms form part of means which I shall now describe -for providing a positive release of the brakes following the venting of the brake cylinder Ca to atmosphere after an application of the brakes, and yalso a means for maintaining the brake shoe i4 in concentric relation with the wheel 4 when the brakesare rel leased'.

The friction arms iii ,are provided Aat their rightehand ends, as viewed in Fig. l, with lspaced fingers 'il which cooperate with the inner surface `of facing on brake head I3 in such manner that the shoe and arms are constrained to rotate as a yunit about'the pivotpin l5, and at their cpposite 'ends'with longitudinal slots i8. The lefthand ends .of the'friction arms straddle a release block I' (see Fig. 5) slidably supported i-n a sup`- 5 porting'memher secured to thetruck' frame. 'A

' block I9 is provided in its left-hand .end with Va recess 2B and has'welded thereto a plate 279 which forms a shoulder'Sll at'the outer end of the recess 28.' A bolt33 extends into the recess 28 through an opening 3l formed in the one end of the supporting'member 2l] and through an aligned opening 32 :provided in the plate 29', and is provided at its 'inner end with a head 33a slidably mounted in the recess 28 and on its outer end with a castel! lated nut 3d llocked in place by a cotter key vt5. A eem'pressed coil spring 36 surrounds 'the'sha'nk of the bolt33 within the recess 28 between the shoulder 3U and the head 33a of the bolt and constantly biases the release block toward the left to the position in which the plate 29 engages the lefthand end of the support 2B as viewed in Fig. 5. It will be apparent, therefore, that the spring 36 will constantly exert on the release block a biasing force which urges the block to the left-hand end of the support Z as viewed in Fig. 5. The operation of the combined release and brake head balancing means will be described in detail hereinafter.

The lowerY ends of the transmitting hanger levers 8 are pivotally connected' by means of a pivot pin Vell with the left-hand ends yof straddle rods 4l and 42 disposed respectively on the inner and outer sides of the wheel d. The outer straddle rod 42 is mounted on the pivot pin inside of the outer transmitting hanger lever 8, as shown in Fig. 3, and is prevented from moving into engagement with the adjacent side of the wheel 4 bymeans of a` spacing sleeve 43 disposed on the pivot pin 4D between the inner transmitting hanger lever 8 and the straddle rod L12. The innerstraddle rod @l is mounted on the pivot pin adjacent the inner side'of the inner hanger lever 8 and is held ill place by a nut .44 screwed onto the inner end of the pivot pin.

rlhe straddle rods are provided at .each .end with pin hole tape ups, and are pivotally connected at the end opposite to the transmitting hanger levers 8 to the lower end of a slack adjuster live lever 45 by'mejans of a pivotpin The straddle rods are maintained in .the desired laterally spaced rela.'- tion -withrespect to the wheel .d at the ends which are Vsecured to the slack adjuster live lever 45 'by means of spacing sleeves and le ,disposed on opposite `sides of the slack adjuster` live lever'. The slack adjuster live lever .d5 extends upwardly between two laterally spaced hangers 4S which are pivotally attached at their Aupperlends tothe truck frame by means of pivot pins 5e, and is pivotally connected intermediate vits ends to .the lower ends of the hangers d Lby means of a pivfot pin 5I, which pivot pin also serves to secure'to the slack adjuster live lever a brake head 52 carrying a brake shoe 53 for frictional ,engagement with the wheel 4 lat the opposite side o1- the rwheel from the brake shoe Hl. Associated with the brake head 52 are friction means 55 of wellknown construction for maintaining the brake shoe 53 in concentric relation' with respect to the wheel 4 When'the brakes are released. Since these means form no part of my present invention. it is believed to be unnecessary to vdescribe them in detail herein.

The upper end of the slack adjuster live lever 45 is curved as shown .and extends through an eye Sii formed in the one arm ella of atransversel'y extending adjusting lever 5?. 'The adjusting lever .51 is pivotally'atta'ched yinteri-nediate its ends by means of 'a pivot pin 'to the truck frame and is provided at its outer end with an arm A5'ib which for clearance reasons is odset downwardly from the other arm a. The free 1 end of the arm 57h is operatively connected` with an automatic slack adjuster SC.

The slack adjuster @C is secured through the medium of a mounting vbracket .69 to 'the outer side of the truck frameV l andv is connected to the brake Cylinder ca by a pipe el. rnis'slac'k adjuster/by itself forms no part of mypresent invention, and may Ycomprise`anyv of"*thewell-Vl known types which will move the effective p'dt of connection of theouter endy of thefoffset ald- Y justing leverl'l toward the left, as viewedn l'iig. 1, a predetermined amount each time that the slack adjuster is supplied with air pressure. The pipe 6I is connected with the brake cylinder Ca at such a point that as long as no slack is present in the lbrake rigging the brake cylinder piston in applying the brakes will not move far enough to admit air to the pipe, but that, when slack develops, the additional movement of the piston necessary to fully apply the brakes will then cause fluid pressure to be admitted to the pipe from the pressure side of the piston and will thus cause the slack adjuster to automatically take up the slack.

When it is desired to apply the brakes, fluid pressure is supplied to all four brake cylinders simultaneously. The fluid pressure supplied to the brake cylinder Ca will force the piston rod 5 of this cylinder outwardly toward the left, as viewed in Fig. l, and hence will cause a corresponding movement of the upper end of the floating brake cylinder lever 6. The movement of the upper end of the lever E toward the left, in turn, will cause this lever to fulcrum about the pivot pin 'I until the brake shoe I4 has been moved into engagement with the wheel 4, whereupon the lever 6 will then iulcrum about the pivot pin I5 and will thus cause the transmitting hanger levers 8 to rotate in a clockwise direction about the pivot pins 9. This latter rotation will act through the straddle rods 4I and 42 to move the lower end of the slack adjuster live lever 45 toward the left, and since the upper end of the slack adjuster live lever is held in a xed position except when slack develops, the movement of the lower end of the slack adjuster live lever 45 toward the left will cause the slack adjuster lever to rotate in a clockwise direction about its point of connection with the adjusting lever 51 to the position in which the brake shoe 53 frictionally engages the wheel 4. -The parts are so proportioned that when the brake shoes I4 and 53 have both moved into engagement with the wheel 4, they will exert on the wheel substantially equal and opposite braking forces as is customary in clasp brake designs.

It will be obvious that when the brake shoe I4 moves into engagement with the wheel 4 in response to an application of the brakes, the friction arms I6 will be constrained to move with the brake shoe, and it Will be remembered that I these friction arms are urged into frictional engagement with the sides ci the friction block I 9 by a force which depends upon the stiffness of the spring 25 and the adjustment of the nut 21 so that the movement of the brake shoe I4 toward the wheel will cause a force to .be exerted on the friction block in opposition to that due to the spring 36. The friction arms I6 are normally clamped against the friction block by the spring 25 in such a position that when the brake rigging is in its released position and the friotion block occupies its extreme left-hand position to which it is biased by the spring 36, the brake shoe I4 will be spaced from the wheel 4 a sufcient amount to prevent the brake shoe from dragging, and the stiffness of the spring 25 is such and the nut 2l is so adjusted that the friction block and lever will normally be constrained to move as a unit when the brakes are applied or released, but that, if the movement of the brake shoe I4 necessary to cause a brake application subsequently increases due to brake shoe or wheel wear, the friction arms I6 will then slide relative to the friction block I9 to a new position. It will be seen, therefore, that When shoe and tire wear, and also to prevent damage to the parts in the event of abnormal displacement of the parts for any reason.

It should be particularly pointed out that due to the fact that the friction arms I6 are pivoted on the same pivot pin which fastens the brake head to the floatingbrake cylinder lever 6 and are provided with lingers which engage the inner surface of facing on brake head I3 the up and down movement of the wheel 4 relative to the frame which takes place due to irregularities in the roadbed will cause the rear end of the friction arms I6 to tend to swing upwardly and downwardly, and it is for the purpose of permitting the necessary movement of these friction arms relative to the friction block I9 and support 22 that the vertical slot 22 is provided in the friction block I9.

It should also be pointed out that due to the inclined position of the arms I6, the brake shoe I 4 will be held concentric to the wheel 4 when the brakes are released, thus preventing brake shoe dragging difficulties.

It will be obvious that if slack develops in the brake rigging, the resultant additional movement of the piston of the brake cylinder Ca necessary to effect a brake application will act to :admit fluid pressure to the slack adjuster SC in the manner outlined hereinbefore, and the fluid pressure thus admitted to the slack adjuster will cause the fulcrum block of the slack adjuster to move toward the right and thus rotate the onset adjusting lever in a counterclockwise direction as viewed in Fig. l, a suicient amount to take up the slack.

One advantage of brake rigging embodying my invention is that relatively few parts are required, which parts are all disposed in positions where they are accessible and have ample clearances irrespective of the fact that the available space for the brake rigging is extremely limited for the reasons pointed out hereinbefore.

Although I have herein shown and described only one form of brake rigging embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a brake rigging, the combination with a truck frame and a supporting wheel therefor, of hangers pivotally supported from said frame on one side of said wheel and hanger levers pivotally supported from said frame on the other side of said wheel, a slack adjuster live lever' and a brake cylinder lever pivotally supported intermediate their ends by means of said hangers: and hanger levers respectively, means connecting said hanger levers with one end of said slack adjuster live lever, a relatively fixed fulcrum for the other end of said slack adjuster live lever, means for frictionally engaging the opposite sides of said wheel carried by said brake cylinder lever and 'tivelyA` xed fulcrumv meansI for theupperA end ef Seld' Sleek "edlllet-evv live. leve/1i. e' .heiliger lever. pivotally suspended from the truckfrarne atvtlie otherl sidev of said wheel, means, connecting tlie lower end of saidfslack adjuster livrlevjerr'with the loweend of hsaidwh'an'er lever, abake vCylin'dri vlever pivotally'y attaehed intermediate its e'ld's'fto said hanger/leverintermediate its. elld rfieene. 'se'elred tdi tlle level-l elle el, e. d; blelee cS/lir'ider'leverand*` to said slack adjusterliveleyer l intermediate'its ends' fofr 'ritiorially engaging said wheel, and a brake cylinder 'operatively' conf neot'ed'with the upper end-'of A{saicllarake cylinder lvr-.

3l In a brake rigging, the combinationwtlra, truekframe and'a'sup'por'tingV wheel-therefor, of hangers pivotauy sappertedfolh saidlframe 'at ne'fs'i'de of said vvl'n'efelV and hanger levers 'pit/7 otallysupprted 'from said frai'e'atthefotner side of said Wheel, a, slack adjusterlivnelever and alorallze4 cylinder lever pivotalljr supporter-lintermediate their ends by means of' said hangers and hangerlever respectively, means connecting-"said, hanger levers with one end'of said sleek adjuster live lever, an automatic slaek"adjuster"opera-v tivelylconriectedwth.the other end of said live lever., means. for frictionally-engaging. the Afdpposite. sides'of said? wheelloarriedby said brake cylinderlever fand said-live lever, and -a loraleeA cylindersconnected with said brake cylinder.lever. el. InaQbrake rigging, the com lo'nationV with a truckiamean'd a supporting wheel-therefor, 'of' al hangr...pivotal1y 'spported from said-frame atloneside of said Wheel and a hangverlever piv otally. suspende'dfrom the truckfframe atthe otheitside of said wheel, a wslack adjuster live lever pivotally attached intermediate its' ends to the lowerencl .of saidfhanger, anautornatic lslack adjuster .operatively connected with the upper end of.` said.. slack adjuster Alive lever, meansA connect.- ing `tltleulower endioi said .slack adjuster Alivelever with. ythe 1ow.er..en`d.`of. saidllianger4v lever,l a brake f cylinder lever pivotally.attachedfintermediate its ends to.said..hanger lever intermediate its ends,- meanssecured .to the lower end o'f said :brake cylindenlever .andto said. slack adjuster liveV lever intermediate. its endsfor frietiona1ly .engaging said wheel,.and a brake eylinderoperatively con.-V`

neoted with the .upper enclofsaidllorakevcylinder lelllk 5. In a brake rigging, the combination withca rtruhel;I framesandia supporting wheel ..therefor',of

hangers and hanger levers pivotally supportedere, speeztivelvfreniA said -frdlll1.l.9ll,.opposite .sides of said wlie ,e1,lV ya.slaclgadjusterllive lever and a brake',

cylinder; lever p iv oetally'l supported. respectively.4

iritfelllledldte their. ends. bvlmeans.oisaidhangers.

hanger. levers, ,means corllecting;.Said hanger. leviers ,l with onel end of said `Slellle adjuster.. live. lever anautematle.Slaekedjuster.securedtosaidf tra e ogtboar'dofthe/Wheels atransversely exs telldl Stlllglever. plvetallv-supported inter-.- medi ende -elldf01lereltlvelrcenneetine.- said; Sl Y V ster, witlii4 the, other wvend.: of said-:live le means* restrictionally engaging... the oppo-.j

, sides, of,I Said kvvlleel l. carriede bv said l brake., der Ylevenand4 said l live\.1ever., and .1. a... brake,

evlleder eerllleeted' .vvltli seldbraleeevllnder.level blllkle rigging, the eemblnatien. with. e trllele' frame and, 'a silpdertlllg Wheel tlleielerlei al lleidael@ pvetallv. Suspended frere tile trllieli.. frame 'at elle Side 0f` Salad. Wheel and.. heiliger L' plvptdllv Sileperldecll` from Vthe. truekl flame, at' tll. "ether Slde. el Said wheel,` a slack; adjuster. live.V lev. plvetellv etteehedlntermedldte lts'erlde.. to the lower endfof said hanger, an automati elaslkledldeter Seeuredieeaid frame outboard el the. wheels., a. transversely extendida a ust lever pivotally supported' intermediate. its. Q and operatively eenrleetlne'.. sie. sleek.. adjuster with the. otherl endv el eeldllve lever, means een; fleeting.: the lovve` end Qt. Said.I Sleek.. adjuster. lever'. with the. lever! end. el, Seldlleneefr. lever.. lai-alge .cylinder lever. pivotally. attaelledlntermee diateits endsfto said; hanger leverv interme the ende-ref.. Selld'helleerlever.meerde Seellledte. the lower end "of said 'brake cylinder lever, and to said slack;` adjuster livel lever intermediate its endev fery llletlell.allyY ellaeellle Seid Wheeldnd'e. brake. evlnder operatively, eenneeted with the upper endof said brake cylindeplever.

'7. In a brake rigging, the,v combinationwith a` vehicle frame anda suilrlortllg.4 Wheel therefar, Oria pairofnanaers'.pivotallv Suspendedfrelll'sdd frame at Ioneside ofsaidzwheella, slazk-.adjllstel livev lever pivdtallv SllPfPQlted. irlter.mediate4 ts ends, between lsaid hangers4 by` means of a pivot pldmeuntedlrl the. leverv ends foigeeld hangers. a brakehead earrvlllsabrake'shee .fer frletidfldle 1y enea-sine. one` Side .0i said WheelmodlltedQn eaidpivotlpin, Sleek .adiuetine-meapsloperativelv. connectedwith'the upper end vof,saiddslv lgadj ustver live lever, a pair of transmitting ,anger levers pivotally suspended'from` said.;fratrieat-` the. Votliereside e ofsad wheel and.` 'operatively con,- nected at, their lower endsllyl means of,l straddle, rods with, the lower endvf of 'said4 slQQK, ,adjuster livellever, a oatillgbrake cylinder;leverpivotally` supported intermediate itsj ends, between said', transmitting hanger. levers` intermediate. their. ends, a bralehead ycarryinggs. 'a brake shoefor frio;

, tional engagement with theK other sideofY said Wheel,plvdtallvattellhed t0. the. 1Qwer..end0,f, Said brake, Cylinder; lever, -and a. brake, .cylinder enf. erativlelv,connectedwitn the upper endfoi said bralefevlinder lever,

8, Ille. brakerieeing, the eemblrlatdn with; a,j velllele l frame and ,e Supporting. ywheel taeter.. for, of a ,pair of ,hangers pflvetallv suspended `.from said frame at one side oisadjwheel, a slack'adf, iusterllvelever pivotallv, snppeltedintermedidte. its ende.. belv'veerleeldheneere bv .elle di e rivet! pin mounted in `.the ldvver5 ends vof...Said hangers d brake,heedcarrvlneabralee Shoe for. flleftle. `j.. ally enea-girls Qneelde"0i.;Saidwvheelrmennted 5011,., saidplvt'pin,.ianlautomatldslaek:adiuster Oper e. tivelycqnnetedwitlilthe uppervend of said yslal v edl'lletefrllve lever?. ail-ell? el transmitting .henger levers pivotally suspendedifrom said frame vat tl1e.. otlilerrside, ofA said wheel and-,operatively con@ neteduat, their loweryends. by l means Vof straddle rods with. the lever elldef Seid Sla-Cle. adjuster-l livev ley/enau floating brake.. cvlinderlever pive-4 otallv supported .intermediate site.. endS., -bet,ween. said transmitting lianger`- levers intermediate their lends, a brake head carryinga brake slroefor frietionvaleengagementq witln the other side; ,of said` Wheel. elvetellv .etteehed te. .the lever., elldel Seid bralie -cylinderV lever, andambralfzeV cylinder opg..V

eratively'econnected Vwithtlf-1e upper end ,01; said,

ascisse vehicle frame and a supporting wheel therefor, of

a pair of hangers pivotally suspended from said frame at one side of said wheel, a slack adjuster live lever pivotally supported intermediate its ends between said hangers by means of a pvot "f pin mounted in the lower ends of said hangers, a brake head carryingr a brake shoe for frictionally engaging one side ci said wheel mounted on said pivot pin, an automatic slack adjuster, aI

arm offset downwardly and operatively connected Vwith said slack adjuster, a pair of trasmitting hanger levers pivotally suspended from said frame at the other side of said wheel and operatively connected at their lower ends by means of straddle rods with the iower end of said slack adjuster live lever, a floating brake cylinder lever 'r `pivotally supported intermediate its ends between said transmitting hanger levers intermediate their ends, a brake head carrying a brake shoe for frictional engagement with the other side of said v wheel pivotally attached to the lower end of said brake cylinder lever, and a brake cylinder operatively connected with the upper end of said brake cylinder lever.

10. In a brake rigging, the combination with a vehicle frame and a supporting wheel therefor, of a pair of hangers pivotally suspended from said frame at one side of said wheel, a slack adjuster live lever pivotally supported intermediate its ends between said hangers by means of a pivot pin mounted in the lower ends of said hangers, a brake head carrying a brake shoe for frictionally engaging one side of said wheel mounted on said pivot pin, an automatic slack adjuster mounted on said frame outboard of said wheels, an adjusting lever pivotally mounted intermediate its ends on a vertical pivot pin and having two vertically offset arms one of which is operatively connected with said slack adjuster and the other of which is operatively connected with said slack adjuster live lever, a pair of transmitting hanger levers 1 pivotally suspended from said frame at the other side of said wheel and operatively connected at their lower ends by means of straddle rods with the lower end of said slack adjuster live lever, a iioating brake cylinder lever pivotally supported intermediate its ends between said transmitting hanger levers intermediate their ends, a b rake head carrying a brake shoe for frictional engagement with the other side of said wheel pivotally attached to the lower end of said brake cylinder lever, and a brake cylinder operatively connected with the upper end of said brake cylinder lever.

11. In a brake rigging, the combination with a truck frame and a supporting wheel therefor, a pair of transmitting hanger levers suspended `from the truck frame,'a iloating brake cylinder lever pivotally supported intermediate its ends between said hanger levers 'intermediate their ends, means for frictionally engaging one side of the wheel carried by the lower end of said brake cylinder lever, a brake cylinder operatively connected with the upper end of said brake cylinder lever, and means for frictionally engaging the other side oi said wheel operatively connected with said transmitting hanger levers at their lower ends.

12. In a brake rigging,A the combination witha truck frame and a supporting wheel therefor, of a pair of transmitting hanger levers suspended lfrom the truck frame, a floating-brake cylinder 'shoe in vconcentric relation to the wheel vthe parts are in their released positions.

lvlever pivotally supported intermediate its ends between said hanger levers intermediate their ends, a brake head carrying a brake shoe for frictionally engaging one side of said wheel pivotally attached to the lower end of said brake cylinder lever, a brake cylinder operatively connected with the upper end of said brake cylinder lever, means for frictionally engaging the other side of said wheel operatively connected with said transmitting hanger levers at their lower ends, and means operatively associated with said brake cylinder lever and said brake head for biasing the parts to released positions and for maintaining said 'brake when 13. In a brake rigging, the combination with a truck frame and a supporting wheel therefor, of a pair of transmitting hanger levers pivotally attached at their upper ends to said truck frame in parallel spaced relation at the outer side of the wheel, a iioating brake cylinder lever pivotally supported intermediate its ends between said hanger levers by means of a pivot pin mounted in said hanger levers intermediate their ends, a brake cylinder mounted on the truck frame in the same plane as said wheel above the wheel at the inner side of the wheel in an inclined position and provided with a piston rod the free end of which is operatively connected with the upper end of said brake cylinder lever, means for frictionally engaging the outer side of the wheel operatively connected with the lower end of said brake cylinder lever, and means for frictioinally engaging the inner side of said wheel operatively connected with the lower ends of said hanger levers.

14. In a brake rigging, the combination with a truck frame and a supporting wheel therefor, of a pair of transmitting hanger levers pivotally attached at their upper ends to said truck frame in parallel spaced relation at the outer side of the wheel, a floating brake cylinder lever pivotally supported intermediate its ends between said hanger levers by means of a pivot pin mounted in said hanger levers intermediate their ends, a brake cylinder mounted on the truck frame in the same plane as said wheel above the wheel at the inner side of the wheel in an inclined position and provided with a piston rod the free end of which is' operatively connected with the upper end of said brake cylinder lever, means for frictionally engaging the outer` side of the wheel operatively connected with the lower end of said vbrake cylinder lever, and means for frictionally engaging the inner side of said wheel operatively `connected with the lower ends of said hanger le'- `vers by means of rods straddling said wheel.

15. In a brake rigging, the combinationwith la truck frame and a supporting wheel therefor,

'of a pair of transmitting hanger levers pivotally attached at their upper ends to said truck frame 'inV parallel spaced relation at the outer side of the wheel, a oating brake cylinder leverpivotally `supported intermediate its ends between said hanger levers by means of a pivot pin mounted `in said hanger levers intermediate their ends, a

L11 Vdle rods connected with the lower ends of said hanger lever anda "slack adjuster live lever con- ,ne'c'ted at one vend with said straddle 'r'ods for yfrictionallyengaging said wheel at the Yinner .side of the'wheel.- Y

16. In a brake rigging, lthe combination with a truck frame and a supporting'wheeltherefor, of hangers pivotally suspended from th'e Ytruck 'frame at one Yside of said wlr'ie'elV and hangerlevers .pivotallysuspended fromjthe truck frame at the other side o f said WheeLa slackuaduster' live -lever lpiv'otally supported intermediate its ends -by saidrhangers and operatively connected at one en d bymeans of straddle rods with the lower ends of said hanger levers-a Vlorake cylinder live Alever .pivotall-y A.supported intermediate -its jends hy said hanger levers lintermediate the ends of the hanger levers, a brake `cylinder operatively connected with the upper end of -said brake cylinder lever,a slackadjuster-operatively connected Wit-h the vupper -end of said fslack adjuster live `lever, -and ybrake shoes for engaging the opposite vSides of said wheel secured respectively to vthe lower vend of said v`lorake rcylinder llever Iand --to'said slack adjuster -live lever intermediate itsl ends.

1-7. 'In Ya brake rigging, the Ycor-rrbination with a truck -frame and a supporting wheel therefor, of hangers pivotally suspended 'from the truck frame-at-one'side 4of-said wheel and hangerflevers ypivotallysuspended from the truck frame'at the other side `of said wheel, a slack adjuster live lever pivotally vsuppc'irte'd intermediate its ends vby saidhangers*and'operatively*connected at one `e'ndloy means o'f fstraddle rods `witlritheflower-ends of said hanger IeVe'rsafbraKe'cyIinder -live lever pivotally supported intermediate its ends by Vsaid `hanger vlevers intermediate their-ends, "a brake head carrying 4a brake shoe foririctional engage- 'ment withone side di Vsaid wheel pivotally at'- pivot pin whichpivotalli7 spports'said-live lever, a 'brake 'head 'carrying a vbrake shoe for friction'- l'ally engaging'ithe other "side'of said wheel Vpiv *ot'a'lly attached to the lower end 'of 'said Vbrake lcylinderleve'rfand brake 'release means'connected l rimer side .fof said wired-'fa 'smak adjuster Auve Y said brake cylinder'leverfsaid'brakerfelaseimans being constructed to provide `a predetermined yfclearanc'ebetween the-brake shoes andthe wheels `irrespective of brakeshoeor wheel wear.

19. Inabrake rigging for applying clasp brakes vto, a vehicle wheel, the combnatin'vvith 'a ybrake cylinder lever pivotally supported intermediate its fends by means of hangers suspended from 'the truck frame and operatively connected at one end with -a brake cylinder and .provided at the other end with a brake head carrying a brake shoe for 'frictionally engaging the wheel, of "two friction arms pivct'ally supported intermediate their ends in parallel spaced relation on the Same pivot pin which serves to secure said vbrake head -to said brake cylinder lever and provided at one end with means engaging said brake head in -such "manner that said head and saidlyfriction arms are constrained to rotate -as a `unit about said .pvot pin, a friction block slidably supported infarlxed support between the other ends of said friction arms'for limited movement along a 2line .parallel to the axis of said friction arms when said brake headlis in brake .applying position, means jbiasing said -hlock away Vfrom the Wheel, longitudinal slots formed in said Yfriction arms 'opposite said block, a vertical slot formed .in one rend of said block, and apin passing through the slots in said friction arms Yand the slot in said block andprovided with vmeans for causing Isaid friction armste irictionally engage the opposite sides of said block. A -20. In a brake rigging, `for lapplying clasp brakes-tto a vehicle wheel, the combination 'with a brake cylinder lever pivotally supported intermediate its ends by'means of vhangers suspended from the -truck sframe -andwoperatively connected Tat one end with a brakefcylinder-and 'provided-at the otherjend with "a brake headcarrying a ybrake .shoe for frictionally engaging the wheel, of two friction arms .pivotally supported intermediate Itheir ends inparallel spaced relation on the same pivot pin which serves -to secure said Florake V.head to said brake cylinder lever Vand provided at `one end with means engaging -said brake Vhead in such manner jthat said 7head `and -`said friction arms are constrained `to rotate as a -unit about said .pivot pin, airiction block slidably supported inaxed support vloetweenthe other endscf said friction arms for limited movement -along line `parallel to the axis of -said -fricti'on farms'4 when said brake head is `in -brake applying position, means biasing said block away from the wheel, .and means for Vcausing nsaid Yfriction armste `Ir-ictionall-y engage the `opposite sides Vof said block, whereby the fparts are biased to `brake yre*- leasing positions through the medium of said block `irrespective of brake shoe or wheel wear.

y21. In -a fbrake rigging -for a rfour-wheel trailer truck, the Vcombination with each 'wheel of Vthe truck of hangers `pivotall'y suspended from the truck-trame Von-one side Yof the wheel and 'hanger levers suspended rfrom =the truck fir-ame *on the other -side of the wheel, a slack adjuster I'live lever apvotally supported :intermedi-ate its 'ends by said hangers Vand operatively -Mconnected at one end 'by Ymeans of straddle rods 'with the lower v"ends of vsaid fli'angar levers, 'a vvbrake cylinder 'live lever pivotally connected 'intermediate its ends with said hanger 'levei's, a brake cylinder oper- Va'tivelyconnected `with the upperend ofsaid brake cylinder =1ever, fa fslack adjuster operatively connected xwith 'the'upper end 'of "said slackadjust'er 4live lever, and Vbrake Vshoes for *engaging 'the op'- posite sides of said Wheel secured respectively to the 'lower 'endfof said brake cylinder :lever vand to said slack adjuster Alive -lever intermediate its ends.

In a brake rigging, the combination `witha 13 truck frame and a supporting wheel therefor, of a pair of hangers suspended from the truck frame at one side of the wheel, a slack adjuster live lever pivotally supported intermediate its ends in the lower ends of said hangers. a brake head carrying a brake shoe for frictionally engaging the wheel attached to said live lever at its point of connection to said hangers, an automatic slack adjuster secured to the truck frame outboard of the wheels, an oset adjusting lever pivotally supported in a horizontal plane and operatively connected at one end with said slack adjuster and at the other end with the upper end of said slack adjuster live lever, and meansconnected 14 with the lower end of said live lever to move it to brake applying and released` positions.

EMIL G. MUELLER. j

REFERENCES CITED The following references are'of record in the le of this patent:

UNITED STATES PATENTS w Number Name Date '722,930 Wadey Mar. 17, 1903" 1,307,165 Turner June 17, 1919 1,422,125 Pehrson July 11, 1922` 2,163,534 Baselt June 20, 1939 2,245,408 McGowan June 10, 1941 

